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TOPIC: Seyfert 1 Galaxy 1H0707-495


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1H0707-495
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Title: The Closest Look at 1H0707-495: X-ray Reverberation Lags with 1.3 Ms of Data
Authors: E. Kara, A.C. Fabian, E.M. Cackett, J.F. Steiner, P. Uttley, D.R. Wilkins, A. Zoghbi

Reverberation lags in AGN were first discovered in the NLS1 galaxy, 1H0707-495. We present a follow-up analysis using 1.3 Ms of data, which allows for the closest ever look at the reverberation signature of this remarkable source. We confirm previous findings of a hard lag of ~100 seconds at frequencies v ~ [0.5 - 4] e-4 Hz, and a soft lag of ~30 seconds at higher frequencies, v ~ [0.6 - 3] e-3 Hz. These two frequency domains clearly show different energy dependences in their lag spectra. We also find evidence for a signature from the broad Fe K line in the high frequency lag spectrum. We use Monte Carlo simulations to show how the lag and coherence measurements respond to the addition of Poisson noise and to dilution by other components. With our better understanding of these effects on the lag, we show that the lag-energy spectra can be modelled with a scenario in which low frequency hard lags are produced by a compact corona responding to accretion rate fluctuations propagating through an optically thick accretion disc, and the high frequency soft lags are produced by short light-travel delay associated with reflection of coronal power-law photons off the disc.

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XMM-Newton discovers a supermassive black hole
Using new data from ESA's XMM-Newton observatory (a European space telescope built with relevant Italian contribution), astronomers have probed closer than ever to a supermassive black hole lying deep at the core of a distant active galaxy.
The galaxy - known as 1H0707-495 - was observed during four 48-hr-long orbits of XMM-Newton around Earth, starting in January 2008. The black hole at its centre was thought to be partially obscured from view by intervening clouds of gas and dust, but these current observations have revealed the innermost depths of the galaxy.

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A supermassive black hole lurking deep in the heart of a distant active galaxy has been probed more closely than ever before by a team of astronomers that includes Penn State Professor of Astronomy Niel Brandt. Using new X-ray data from the European Space Agency's XMM-Newton satellite, the team observed the galaxy - known as 1H0707-495 - for four 48-hour-long periods, revealing the innermost depths of the galaxy.

"We now can start to map out the region immediately around the black hole" - Andrew Fabian of the University of Cambridge, who headed the observations and analysis.

A research paper describing the team's discoveries will be published on May 28 in the journal Nature.

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RE: Seyfert 1 Galaxy 1H0707-495
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Astronomers are getting a close-up look at a cosmic eating machine: a spinning black hole that devours the mass equivalent of two Earths per hour, verging on the limit of its feeding ability.

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Posts: 131433
Date:
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Using new data from ESA's XMM-Newton spaceborne observatory, astronomers have probed closer than ever to a supermassive black hole lying deep at the core of a distant active galaxy.
The galaxy - known as 1H0707-495 - was observed during four 48-hr-long orbits of XMM-Newton around Earth, starting in January 2008. The black hole at its centre was thought to be partially obscured from view by intervening clouds of gas and dust, but these current observations have revealed the innermost depths of the galaxy.

"We can now start to map out the region immediately around the black hole" - Andrew Fabian, at the University of Cambridge, who headed the observations and analysis.

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Position(2000): RA 07 08 41.47 0.1", Dec -49 33'5.80" 0.1"
V = 15.7

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